Adsorption is employed for the separation of one or more impurities or other substances from a gas stream. Typically adsorbent material, such as molecular sieve, is positioned within an adsorbent vessel on a bed support, and gas is passed into the vessel and through the adsorbent material. As the gas passes through the adsorbent material impurities or other substances are adsorbed from the gas onto the adsorbent material.
It is important for the efficient operation of the adsorption process that the flow of gas be distributed relatively uniformly along and across the adsorbent bed. Non-uniform gas flow is a particular problem for systems employing a vessel having a length which is significantly greater than its width, for example by a factor of at least 1.5 to 1. In such situations the gas inlet system does not distribute the flow of gas uniformly into the expanding head region or into the curved shell regions of such horizontal or longitudinal adsorption vessels.